Replacement of precious single metal catalysts with cost-effective,highly-dispersed composite catalysts for catalytic hydrothermal conversion of residue holds tremendous promise for the residue upgrading technologies....Replacement of precious single metal catalysts with cost-effective,highly-dispersed composite catalysts for catalytic hydrothermal conversion of residue holds tremendous promise for the residue upgrading technologies.Organic metals were added to the feed as the oil-soluble precursors,and were transformed into the catalytic active phases in this work.Physical properties and structures of the composite catalysts had been investigated by X-ray fluorescence spectroscopy,X-ray photoelectron spectroscopy,X-ray diffraction,scanning electron microscopy and transmission electron microscopy.The composite catalysts were found to be highly efficient in the catalytic hydrothermal conversion of both the model compound and the residue.Increased metal dispersion and synergistic effects of two metals played indispensable roles in such catalytic system.Results showed that under the test conditions specified in the article,the catalyst had the best catalytic performance when the mass ratio of molybdenum to iron was 1.5.展开更多
Oxidation-reduction properties of some Fe-S and Mo-Fe-S clusters have been studied by cyclic voltammetric measurement. It is indicated that there are some factors which affect the oxidation- reduction properties of cl...Oxidation-reduction properties of some Fe-S and Mo-Fe-S clusters have been studied by cyclic voltammetric measurement. It is indicated that there are some factors which affect the oxidation- reduction properties of clusters, of which are charge density of metal atom in cluster core, electron effect of ligands, charge and geometric configurations of the reactant particle, etc.展开更多
The freckle formation and their phase characterization in freckle areas were investigated by means of microstructure analysis approaches and a thermodynamic equilibrium phase calculation method in a Ni-Cr-Mo-Fe-W allo...The freckle formation and their phase characterization in freckle areas were investigated by means of microstructure analysis approaches and a thermodynamic equilibrium phase calculation method in a Ni-Cr-Mo-Fe-W alloy. These results show that in freckle areas a large number of M6C, μ and P phases precipitate in grain boundaries even within grain due to the enrichment and segregation of Mo and C during solidification, which results in small grains in freckle areas. Equilibrium phase and liquid segregation calculation can give an reasonable interpretation of the freckle feature for this alloy.展开更多
The characteristic studies, by means of LR, UV-Vis and XPS spectroscopies, of the preparation process of Mo-Co-S and Mo-Fe-S catalysts for HDS and HDN, derived from (NH4)2MoS4-CoCl2 and (NH4)2MoS4-FeCl2 complexes supp...The characteristic studies, by means of LR, UV-Vis and XPS spectroscopies, of the preparation process of Mo-Co-S and Mo-Fe-S catalysts for HDS and HDN, derived from (NH4)2MoS4-CoCl2 and (NH4)2MoS4-FeCl2 complexes supported on γ-Al2O3, respectively, indicate that the catalytically essential moiety on the surface of the catalysts is dominantly some sulfido-bimetallic species with such a structural unit (M' =Co or Fe), and both Co and Fe, served as promoters, can donate electrons to Mo probably via bridging-S. The nature of active-sites and the mechanism of promotion are discussed according to the results.展开更多
TheNH_(3)-TPDcharacterization wasconducted to confirm that the acidity of Mo-Fe/HZSM-5 zeolite could be selectively modified via the glow discharge plasma treatment.The plasma catalyst treatment could totally change t...TheNH_(3)-TPDcharacterization wasconducted to confirm that the acidity of Mo-Fe/HZSM-5 zeolite could be selectively modified via the glow discharge plasma treatment.The plasma catalyst treatment could totally change the distribution of aromatic products with higher methane conversion compared to the untreated catalyst.Some polycyclic aromatics such as anthracene,pyrene and phenanthrene were also produced over the plasma treated catalyst,in addition to benzene,toluene and naphthalene,which were normally obtained over the untreated catalyst.展开更多
Reaction of [Mo3(CO)7(S,O-C6H4-1,2)3]2- with FeCl2 in MeCN at 60℃ affords a new Mo-Fe-S cluster complex containing MoO3S3 unit and mixed-valeut Mo atoms, [Et4N]2[Mo2Fe-(CO)4(O,S-C6H4-1,2)aCl2] (1). 1 is characterized...Reaction of [Mo3(CO)7(S,O-C6H4-1,2)3]2- with FeCl2 in MeCN at 60℃ affords a new Mo-Fe-S cluster complex containing MoO3S3 unit and mixed-valeut Mo atoms, [Et4N]2[Mo2Fe-(CO)4(O,S-C6H4-1,2)aCl2] (1). 1 is characterized by elemental analysis, IR, Mossbauer spectra, X-ray photoelectron spectra and mass spectra. And the structure of 1 is suggested as the structure which contains a [Mo(S,O-C6H4-1,2)3] unit of which the two of three sulfur atoms link to a Mo(CO)4-moiety and the three oxygen atoms are coordinated to a FeCl2 ligand.展开更多
Nanocrystalline Ni Mo Fe alloy deposits were obtained by electrodeposition. The structures of the alloy deposits were analyzed by X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS). The XRD results...Nanocrystalline Ni Mo Fe alloy deposits were obtained by electrodeposition. The structures of the alloy deposits were analyzed by X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS). The XRD results of nanocrystalline Ni Mo Fe alloy deposit show that many diffraction lines disappear, and that there is only one diffraction peak at 44.0°. The XPS results of nanocrystalline Ni Mo Fe alloy deposits indicate that the nickel, molybdenum and iron of the deposits exist in metallic state, and that the binding energy of the alloyed elements increases to some extent. The nanocrystalline Ni Mo Fe alloy deposit electrode may offer better electrocatalytic activity than the polycrystalline nickel electrode and the nanocrystalline Ni Mo alloy electrode. The electrochemical impedance spectra from the nanocrystalline Ni Mo Fe alloy electrode indicate that hydrogen evolution in 30% ( m/m ) KOH at lower overpotential is in accordance with the Volmer Tafel mechanism, but with the Volmer Heyrovsky mechanism at higher overpotential.展开更多
基金This work is financially supported by the China Petroleum and Chemical Corporation(SINOPEC 120063-1).
文摘Replacement of precious single metal catalysts with cost-effective,highly-dispersed composite catalysts for catalytic hydrothermal conversion of residue holds tremendous promise for the residue upgrading technologies.Organic metals were added to the feed as the oil-soluble precursors,and were transformed into the catalytic active phases in this work.Physical properties and structures of the composite catalysts had been investigated by X-ray fluorescence spectroscopy,X-ray photoelectron spectroscopy,X-ray diffraction,scanning electron microscopy and transmission electron microscopy.The composite catalysts were found to be highly efficient in the catalytic hydrothermal conversion of both the model compound and the residue.Increased metal dispersion and synergistic effects of two metals played indispensable roles in such catalytic system.Results showed that under the test conditions specified in the article,the catalyst had the best catalytic performance when the mass ratio of molybdenum to iron was 1.5.
文摘Oxidation-reduction properties of some Fe-S and Mo-Fe-S clusters have been studied by cyclic voltammetric measurement. It is indicated that there are some factors which affect the oxidation- reduction properties of clusters, of which are charge density of metal atom in cluster core, electron effect of ligands, charge and geometric configurations of the reactant particle, etc.
基金supported by the National Natural Science Foundation of China(No.50371006)the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE,China
文摘The freckle formation and their phase characterization in freckle areas were investigated by means of microstructure analysis approaches and a thermodynamic equilibrium phase calculation method in a Ni-Cr-Mo-Fe-W alloy. These results show that in freckle areas a large number of M6C, μ and P phases precipitate in grain boundaries even within grain due to the enrichment and segregation of Mo and C during solidification, which results in small grains in freckle areas. Equilibrium phase and liquid segregation calculation can give an reasonable interpretation of the freckle feature for this alloy.
基金Supported by the National Natural Science Foundation of China
文摘The characteristic studies, by means of LR, UV-Vis and XPS spectroscopies, of the preparation process of Mo-Co-S and Mo-Fe-S catalysts for HDS and HDN, derived from (NH4)2MoS4-CoCl2 and (NH4)2MoS4-FeCl2 complexes supported on γ-Al2O3, respectively, indicate that the catalytically essential moiety on the surface of the catalysts is dominantly some sulfido-bimetallic species with such a structural unit (M' =Co or Fe), and both Co and Fe, served as promoters, can donate electrons to Mo probably via bridging-S. The nature of active-sites and the mechanism of promotion are discussed according to the results.
基金The support from the State Key Development Program for Basic Research of China(Grant No.2005CB221406)the National Natural Science Foundation of China(Grant No.20490203)are much appreciated.
文摘TheNH_(3)-TPDcharacterization wasconducted to confirm that the acidity of Mo-Fe/HZSM-5 zeolite could be selectively modified via the glow discharge plasma treatment.The plasma catalyst treatment could totally change the distribution of aromatic products with higher methane conversion compared to the untreated catalyst.Some polycyclic aromatics such as anthracene,pyrene and phenanthrene were also produced over the plasma treated catalyst,in addition to benzene,toluene and naphthalene,which were normally obtained over the untreated catalyst.
基金Project supported by the National Natural Science Foundation of China.
文摘Reaction of [Mo3(CO)7(S,O-C6H4-1,2)3]2- with FeCl2 in MeCN at 60℃ affords a new Mo-Fe-S cluster complex containing MoO3S3 unit and mixed-valeut Mo atoms, [Et4N]2[Mo2Fe-(CO)4(O,S-C6H4-1,2)aCl2] (1). 1 is characterized by elemental analysis, IR, Mossbauer spectra, X-ray photoelectron spectra and mass spectra. And the structure of 1 is suggested as the structure which contains a [Mo(S,O-C6H4-1,2)3] unit of which the two of three sulfur atoms link to a Mo(CO)4-moiety and the three oxygen atoms are coordinated to a FeCl2 ligand.
基金theNationalNaturalScienceFoundationofChina (No .2 0 0 73 0 3 7)theMajorStateBasicResearchDevelopmentProgram (No .2 0 0 2CBZ 1180 0 )
文摘Nanocrystalline Ni Mo Fe alloy deposits were obtained by electrodeposition. The structures of the alloy deposits were analyzed by X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS). The XRD results of nanocrystalline Ni Mo Fe alloy deposit show that many diffraction lines disappear, and that there is only one diffraction peak at 44.0°. The XPS results of nanocrystalline Ni Mo Fe alloy deposits indicate that the nickel, molybdenum and iron of the deposits exist in metallic state, and that the binding energy of the alloyed elements increases to some extent. The nanocrystalline Ni Mo Fe alloy deposit electrode may offer better electrocatalytic activity than the polycrystalline nickel electrode and the nanocrystalline Ni Mo alloy electrode. The electrochemical impedance spectra from the nanocrystalline Ni Mo Fe alloy electrode indicate that hydrogen evolution in 30% ( m/m ) KOH at lower overpotential is in accordance with the Volmer Tafel mechanism, but with the Volmer Heyrovsky mechanism at higher overpotential.
